Method of making compressed elastomer-bonded hair products



IAug. 20, 1957 E. w. COLT ET AL. 2,803,577

METHOD oF MAKING COMPRESSED ELAsToMER-BONDED HAIR PRODUCTS Filed June26, 1952 Arrow/Ek United States Patent Oiice Patented Aug. 20, 1957METHOD F MAKING COMPRESSED ELAST()- MER-BON DED HAIR PRODUCTS Edwin W.Colt, Evanston, and Sidney N. Pinhasik and Frank D. Sulc, Chicago, Ill.,assignors to Armour and Company, Chicago, Ill., a corporation ofIllinois Application June 26, 1952, Serial No. 295,654

Claims. (Cl. 154-110) :This invention relates to a method of making4compressed elastomer-bonded hair products, such as underrug pads,cushions, etc.` The method of this invention has particular utilityV inmaking under-rug pads from hog hair.

Elastomer-bonded hair products for use in upholstering furniture haveheretofore been prepared. The general process for preparing suchproducts involves the steps of (1) spreading curled hair either manuallyor mechanically in a mat or web, (2) spraying the Web with a compoundedlatex to bind the hair laments together, and (3) curing the sprayed matto vulcanize the latex. Such upholstering mats are generally prepared inthicknesses of between about l to 4 inches. These mats are generally inthe form of at sheets, having densities in the range from about 28 to 46ounces per cubic foot, and being capable of supporting loads up to about2.5 pounds per square inch. i

For Ysome purposes, however, it would be desirable to increase theloading capacity of the elastomer-bonded hair mats. One way of doingthis is to increase the density of the hair mats, but in order toincrease the density of the mats from that obtained by the randompositioning of the hair it is necessary to compress the hair mat and setit in compressed condition. Also, in order to form non-rectilinearproducts such as rounded hair cushions, `etc., from rectilinear blocksof hair, it is necessary to compress the hair blocks and set them incompressed condition. In the course of the experimental Work leading tothe present invention it has been found that it is completelyimpractical to hold the hairmats or pads in compressed condition untilthe latex is vulcanized, which would normally require from 30 to 60minutes. To overcome this difficulty it was suggested that the naturallatex composition can be dried until it becomes indispersible but beforeit has cured to any appreciable extent. Natural latex is tacky in thisstate and has `adhesivity properties. Therefore, it would seem to befeasible to compress the hair mat and hold itin compressed conditionuntil the latex has adhesively bound the hair ftlaments in compressed`condition. Thereafter, the cornpressed hair mats could be vulcanized topermanently bindthe hair. Even when natural latex is employed and it iscarefully dried to an indispersible but unvulcanized condition in whichit has maximum adhesive properties, it is found that the compressing ofthe hair mat to preliminarily set it in compressed condition requires anexcessive amount of time. Depending somewhat on the degree ofcompression to which the mat is subjected, it has been found to requireas much as 5 to l5 minutes to obtain a complete set at the desiredthickness or shape. As thel time interval in which the pad is forciblyheld in compressed condition is shortened, the degree of recovery of thepad to its original thickness increases. This rebound effect is bothvariable and substantial at short time intervals, say in theneighborhood of 1 to 2 minutes. Therefore, it can readily be appreciatedthat a process employing this operation is not suited for highspeedproduction lines, such as would be required to produce under-rug padsefliciently. In a continuous production line for under-rug pads it wouldbe desirable to pass the uncompressed hair web over a compressing rollbefore it has passed into the vulcanizing ovens. The required time ofcontact with the compressing roll would therefore limit the speed of theentire production line, and contact time in excess of 2 minutes wouldgreatly reduce the commercial value of the process. Compressing rolls ofvery large diameter could be employed, but these would add to theexpense of the equipment and would prevent the operation from beingcarried out on a; compact production line. The required compressing timeto set the hair pads in compressed condition would also be an importantfactor in molding operations where blocks of latex-coated hair areplaced in a mold and compressed to form rounded cushions and othercurvilinear shapes.

It is therefore a general object of this invention to provide a methodof making compressed elastomer-bonded hair products which are adaptedfor efcient, high-speed production. More specifically, it is an objectof this invention to provide a method by which mats or blocks of haircan be compressed and set in desired compressed condition in a veryshort interval of time. It is a further object of this invention toprovide a method by which a synthetic elastomer can be used in place ofnatural latex as the primary ingredient of the elastomer-bondingcomposition in. making compressed elastomer-bonded hair products, eventhough synthetic elastomers have considerably poorer adhesive qualitieswhen dried to an in-` dispersible but unvulcanized state. It is aspecific object of this invention to provide a method adapted forftheproduction of under-rug pads which are formed by subjecting hair webs toa high degree of compression on a continuous processing line, and inwhich all operations are performed Without severing the web. Furtherobjects and advantages will appear as the specication proceeds.`

The method of this invention is shown in illustrative embodiments in theaccompanying drawing, in Which- Fig. 1 is a partial diagrammatic view ofa production line for making highly compressed elastomer-bonded hairproducts such as under-rug pads; Fig. 2, the rest of the production lineof which the lirst portion is shown in Fig. l; and Fig. 3, adiagrammatic representation of a mold which can be employed forproducing compressed curvilinear hair products from rectilinear hairblocks in accordance with the method of this invention. l

The starting material for use in the process of this invention can bedesignated as curled animal hair. The term hair is used in thisspecification and claims in its broader sense as referring totilamentary epithelial tissue composed mainly of keratin, or in otherwords it includes Wool as well as the other common types of commercialanimal hair such as horse hair, cattle hair, and hog hair. Preferably,however, the hair for use in the method of this invention has an averagediameter of between about 2.5 to 9.0 mils, which excludes Wool since ithas an average diameter of l mil or less. Specifically desirable typesof hair from both an economic and functional standpoint are relativelyshort hair such as hog hair and cattle body hair; however, long types ofhair such as cattle tail hair, horse mane hair, etc., can be employed.Excellent results are obtained with hog hair, which can contain a minorpercentage by weight of other types of hair such as cattle tail hair.The term curled means that the natural hair laments have had athree-dimensional curvature impressed on them by a curlingprocess. Forexample, the hair can be curled by the well-known mechanical curlingprocess, or it can be curled by the more recently developed chemicalcurling process. It is not absolutely necessary that curled animal hairbe exclusively employed, although this is desirable. Synthetic fibers orfibers of vegetable origin can be used in minor proportions by weight.

As indicated above, the curling of hair by either mechanical or chemicalprocess introduces a three-dimensional curl in the hair filaments sothat a random distribution of the hair on a flat surface produces astereoreticulate mass thereon which will produce a hair web ofapproximately the same density for the same kind of hair having aboutthe same degree ofV statistical curl. The curling of the hair is awell-known process and does not constitute a part of the presentinvention. Therefore, it is believedl that it will not be necessary tofurther discuss it herein.

The initial step of the present process involves the spreading of thecurled animal hair in a layer of the desired thickness. This may beaccomplished either man-v ually oir-mechanically, andV preferably thehair is allowed to fall on a horizontal surface so that it assumes arandom distribution and forms a hair mat or web of a predetermined bulkdensity. For the preparation of under-rug pads, a hair web or mat ofbetween about 2 to 3 inches in thickness is preferred, but for themanufacture of hair cushions, etc. somewhat greater thicknesses may bedesirable, say upV to about 4 inches.

Referring to Fig. 1 of the drawing, there is shown in somewhatdiagrammatic form mechanical apparatus for carrying out the first stepof the present process. The curled hair is stored in hopper 10 and feddownwardly onto a slide 11 from which it is discharged into a hairspreader 12. In the illustration given, hair spreader 12 is equippedwith wire-toothed carding cylinders 12a and 12b, which separate thefibers as they are discharged from slide 11. Hair spreader 12 lalsoincludes two lower positioning rolls 12e` and 12d. The fluffy mass ofhair H is discharged downwardly by the carding rolls 12a and 12b andpositioning rollst12c and 12d onto a continuous conveyor belt 13 whereit is formed'into a web W of the desired thickness.

Following the formation of the flat hair mat or web, it is sprayed withan elastomer forthepurpose ofbonding the hair filaments together. One orboth sides of the web can be sprayed, and a plurality of spraying onboth sides can be used if desired. With webs of about 2 to 3 inches inthickness, it has been found'desirable to spray the web a singletimefrom each side. This gives excellent penetration by theliquidelastomer` dispersion and prevents the dispersion from collecting on theconveyor or other supporting surface because thebottorn half of the webacts as a filter during each spraying operation.

Referring again to Fig. l of thev drawing, the web W is shown beingcarried toward the right from hair spreader 12 by conveyor belt 13 to aspraying station i" or zone 14 wherein one side of theweb is sprayedwith the liquid elastomer dispersion. In the illustration given, thereis shown a sprayhead 15, which is preferably of the oscillating type sothat it moves backL and forth across the web during the sprayingoperation. Sufficient elastomer is applied at spray station 14 topenetrate the upper half of the web. Immediately thereafter conveyorbelt 13 takes the partially elastomer-coated web-through a dryer 16wherein the elastomer coating ,isdried sufficiently to increase thetensile strengthk of the matv so that it can be inverted4 without`tearing the mat,V and also so that the elastomer coating Lwillnot stickto the conveyor belt or drain downwardly uponit whenthe web is inverted.Ordinarily, the time requiredk in dryer 16 will be between about.l5 toZOseconds when a dryer of the hot air. blast type is employed. Thepartially coated web W is then taken over an inverter 17vwhich turnsover the web so that the uncoated portion of the web is now uppermost onthe conveyor 13. The web is then conveyed through a second sprayingstation 18 similar to spraying station 14. If desired, it may beequipped with an oscillating sprayhead 19 of the same type as sprayhead15. Sufficient elastomer is applied in spray station 18 to penetrate tothe center of the web and thus complete the distribution of theelastomer throughout the web.

When the elastomer is applied by spraying as preferred, it is found thatnot only are the individual filaments coated with films or sheaths ofthe elastomer, but also that the elastomer tends to accumulate at thecross-points or intersections of the hair filaments and to form noduleswhich effectively lock the hair filaments together. Both thedistribution of the elastomer on the hair filaments and the forming ofnodules at the intersection of the hair filaments is desired, but it isbelieved that the nodules are of greater importance in imparting thedesired mechanical properties to the hair mat.

Various types of elastomer dispersions can be employed. However, it isvpreferred to employ an aqueous dispersion of a vulcanizable elastomer.The specific elastomer employed may be either natural rubber (latex), asynthetic elastomer, or a reclaimed rubber dispersion. The rubber orsynthetic elastomer dispersion is com pounded with well-knowningredients to facilitate the application and curing of the elastomer.Water may be added to secure required consistency for application. Asindicated previously, when an aqueous dispersion of natural rubber isdrie'd to an indispersible state in which it is not appreciably cured,it has a relatively high adhesivity. lt was expected that the propertyof high adhesivity in an indispersible but uncured state would beessential for the elastomer employed in making compressedelastomerbondedhair products. However, it has now been discovered thatwhen the method of this: invention is employed, and particularly oneessential step thereof which will subsequently be described in detail,that a natural rubber elastomer does not possess any substantialadvantages over a synthetic elastomer, even though the syntheticelastomer has much poorer adhesive qualities inits indispersible butunvulcanized state. It is desired to emphasize the importance of thisdiscovery, since it permits compressed elastomer-bonded hair products tobe made entirely from domestic raw materials. For eX- ample, syntheticelastomer such as butadiene-styrene'dispersions, neoprene rubberdispersions, etc. can be advantageously employed.

Typical formuliof compounded, vulcanizable aqueous dispersions ofelastomers are set outv below:

Natural rubber formulation Parts by weight (dry) Naturalrubber latex(62% solids) 100.0` 20% potassium hydroxide solution 0.5 5,0% zinc oxidedispersion 3.0 65% sulphur dispersion 2.0 50% agerite white dispersion0.5 50% zinc salt of mercaptobenzothiazole 1.0 50% zincdibutyl-dithiocarbamate i 0.5

Synthetic elastomer formulation Parts byweight (dry) Neoprene latex`(50%solids) 100.0 Aquarex- D 1.0 50% zinc; oxide dispersion 20.0 50%.lageritefwhitedispersion 1;0 50% zinc dibutyl dithiocarbamate 2.0

v to an indispersible but substantially unvulcaniz'edstate 4of waterinthe hair mat is not especially desirable.

is Ato dry the hair mat until the bulk of the water is re' moved fromthe elastomer dispersion. Generally, it is satisfactory to remove atleast about 60% of the water and preferably 80% or more of the water.This can be done very rapidly in a hot air blast drying oven. Forexample, the time required in the ordinary oven of this type wouldgenerally not exceed 15 to 20 seconds. The normal initial moisturecontent of curled animal hair is around by weight. After application ofthe elastomer, of course, the moisture content of the hair is somewhatincreased. However, after the drying step in which the bulk of the wateris removed from the elastomer dispersion, the moisture content of thehair is probably `returned to around 10% or lower.

In Fig. 2 of the drawing the completely impregnated web W after thecompletion of the operations illustrated in Fig. 1 of thedrawing, isshown being carried into a dryer 20. Dryer 20 is preferably of the hotair blast type and the drying conditions are regulated so that the bulkof the water is removed from the elastomer while the web W is passingthrough dryer 20. Thus, upon being discharged from dryer 20, the web isready to undergo the compression step which characterizes the process ofthis invention.

After completion of the drying operation in which the elastomer isconverted to an indispersible but unvulcanized state, the web willordinarily have a density of between about 28 to 46 ounces per cubicfoot. As indicated previously, in order to -increase the density of theweb, it is necessary to compress it and set it in compressed condition.A similar compressing operation is required to form curvilinear productsfrom rectangular blocks of hair which can be cut from a tlat web. It hasbeen found to be important to heat the web to a relatively hightemperature during the compressing step. This can most advantageously becarried out by contacting at least one of the sides of the web with aheated surface at a temperature between about 212 to 300 F. If desired,both sides of the web can be contacted with heated surfaces and this ispreferred. Preferably, at least one of the heated surfaces is at atemperature between about 230 to 280 F., and excellent results areachieved when one or both of the surfaces is at a temperature betweenabout 260 to 275 F. However, in the course of the experimental workleading to the present invention, it has been determined that hightemperatures are not alone sufficient for high-speed operation whereinthe web is completely set in compressed condition in a minimum of time.In combination with the high temperature it has been found necessary toemploy the action of water at or near the boiling point, or preferablyto maintain the hair in contact with an atmosphere containing steamduring the compressing step. Satisfactory results can be achieved bycontacting the hair with water at a temperature of 212 F. or above, butit is preferred to inject dry steam into the web along linesapproximately normal to the ilat surfaces of the web simultaneously withthe compression step in which at least one surface of the web iscontacted with a heated member. The steam should have some degree ofsuper-heat, as condensation The steam can be introduced into the webimmediately prior to the compressing step, or the web can be sprayedwith hot water which is converted into steam by contact with the heatedsurfaces in the compressing zone. However, the injection of dry steamalong lines normal to the surface of the web simultaneously with thecompressing step has been found to give the best results, and istherefore preferred. Among the results accomplished by the contacting ofthe hair with an atmosphere rich in steam are the following: (l) theheat transfer to the hair web is greatly accelerated; (2) the steamtreatment temporarily reduces the bending modulus of the hair andtherefore `facilitates the compressing operation; (3) the combina- ;tionof heat and the moist atmosphere superimposes a set to the curl of thehair in the new position, which in effect relieves the undesirablestresses in the hair which tend to produce rebound, while at the sametime setting the hair in a condition of high resiliency at the desiredthickness.

lt has been determined that for best results the moisture content of thehair during the compressing step should be increased to between about l5to 25% by weight. However, a sufficiently precise regulation of themoisture content of the hair can easily be obtained by the injection ofdry steam as outlinedabove. Moreover, if the injected steam containssufficient super-heat to raise the temperature of the pad above 212 F.and preferably to between 260 to 280 F., one or both of the surfacesbetween which the pad is compressed can be at a temperature considerablybelow 212 F. For example, the injection of steam at 30 to 100 p. s. i.g. can be used satisfactorily even though the compressing surfaces arenot heated. The injection of steam along lines substantially normal tothe flat surface of the web effectively meters the moisture to theindividual hair filaments, thereby increasing their moisture content togreater than 15% by weight, without undue condensation of moisture onthe outside of the hair filaments. This even metering of the moisture tothe individual hair filaments is believed to be of value in achievingthe repositioning and stabilizing of the hair in the compressedcondition.

One of the main advantages of using the combination of high temperaturesand steam injection in forming cornpressed elastomer-bonded hairproducts is that the required compression time to completely reset thehair can be reduced to from 25 to 5% of that required if hightemperatures alone were employed. A further advantage is that asynthetic elastomer can be employed as the bonding agent even though inits indispersible but unvulcanized state it has relatively poor adhesiveproperties as compared with natural latex.

Referring to Fig. 2 of the drawing, the dried coated web W is shownpassing upwardly from conveyor 13 onto a compressing and embossing roll22. In the illustration given, roll 22 is heated internally with steamof suicient pressure to maintain the surface temperature of the rollabove 230 F., and preferably between about 260 to 275 F. The compressionof web W against roll 22 is accomplished by means of belt 23 whichtravels around a series of rollers 24, 25, 26 and 27 so that it formswith the surface of roll 22 a channel 28 of the desired width to whichweb W is to be compressed. Belt 23, of course, travels in the samedirection as roll 22, as indicated in Fig. 2, and thereby as web Wenters channel 28 it is progressively compressed to the, desiredthickness and held in this thickness throughout its time of travelthrough channel 28. While the web W is passing through channel 28 steamis injected into it along lines approximately normal to the flat surfacethereof by manifold 35 which rides against the outer surface of belt 23.If belt 23 is of a porous material such as a heavy cloth web, the steamcan be made to penetrate through the belt into the hair. Alternatively,a perforated belt can be employed so that the steam will pass throughmanifold 35 through the perforations in the belt into the hair web. Ofcourse, if desired, other means of introducing the steam can beemployed, such as introducing it through the surface o roll 22, etc.

The compressed web W is discharged from channel 28 and carried throughcuring or vulcanizing oven 30 by means of conveyor 29. At temperaturesbetween about 230 to 240 F. in the vulcanizing oven, from 20 to 40minutes will ordinarily be required to complete the vulcanization. Ifdesired, lower temperatures can be employed with longer times. Forexample, at 220 F. a time `of around l hour may be required to completethe vulcanization. The finished rug underlay is indicated in Fig. 2 bythe number 31, as it isdischarged from the curing oven 30.

Ablocks -movable platen 32 and a stationary platen 33. platens 32 vand33 are heated -by steam, and platen 33 molded. vpad R is indicated indotted lines prior to the compress- AInthe manufacture of under-rugpads-bythe Vmethod of1this invention, it has'been found desirable to-emboss atleast `one surface `of the hair web during the compressingstep. This can be easily accomplished by employing a compressing rollhaving a three-dimensional patternon the surface thereof. lFor example,roll 22 in Fig. 2 of the drawing is shown provided with a rippled orcorrugated outer surface 22a. Various patterns can be embossed on thesurfaces of the rug underlay in this manner, such as diamond shapedpatterns, etc. The simultaneous embossing and Acompressing of the webhas been found to kbe greatly facilitated bythe method of thisinvention. The forming of the surface pattern on the web can be rapidlyaccomplished by the joint use ofsteam and high temperatures, asdescribed above. The value of embossing'the ,surface of the web is thatit increases the tensile strength of the under-rug pad, gives it betterresiliency, and improves'its rolling properties.

This invention is particularly adapted for producing under-rug Ypadsfrom curled hog hair. VWhen it is employed `for this purpose, the matof' hair `formed on the conveyorY should be between about l.5 to 3.5inches and preferably -from about 2 vto 3 inches in thickness. This webis then compressed to a thickness of between about .2 to .8 inch orpreferably from about 3%; to S; inch. The density of the viinished padisincreased to about 75 to 110 ounces per cubic foot from the density ofthe uncompressed web which will usually be between about 28 to 46 ouncesper cubic foot. Because of this high degree of compression7 therepositioning and stabilizing of the hair by the action of thesteam-containing atmosphere and high temperatures of the compressingsurfaces is especially important. For randomly distributed hair on theconveyor belt, it can be assumed vthat substantially the samepercentages of the hair lilaments are oriented in all directions. Forexample, the vertical and horizontal component ofthe randomlydistributed hair mass would be approximately 50-50. However, ondecreasing the thickness of the hairweb by 4 to 6 times, as is requiredfor the production of under-rug pads, the vertical component ofthe hairviilarnents is greatly decreased. For example, the vertical component ofthe hair filaments in the highly compressed under-rug pads may beconsiderably lessthan 10%. 'When ahog hair web is compressed from -2inches to f/s inch, it has Vbeen found `that the vertical component ofthe hair is around 6%. The combined action -of steam and hightemperatures, however,

-eiectively -repositions and stabilizes the hair with this lradicallyaltered alignment of the lilaments.

The hair web either before or after the compressing and curing steps can4beeasily'cut with rotar-y cutters to pro* duce a firm edge. Therefore,the finished under-rug pads can be readily `cut in the desired length,or prior to the compressing step the web can be cut into rectangular forindividual molding operations to form cushions, etc. In Fig. 3 of thedrawing, there is shown somewhat diagrammatically a molding press Phaving a Both is provided with a `plurality of apertures 33a throughwhich steam is discharged into the hair pad as it is being In theillustration given, a rectangular hair "pressed condition, valve 1Minthe steam line of stationary -platen 33 is opened so that steam passesinto hair pad R through apertures 33u. v -forming the hair pads intocurvilinear products such as hair cushions are .substantially thetsameasthose pre- The desirable temperatures for viously described forforming under-rug pads. Therefore,

it is'believed that it will knot be Ynecessary -to Vrepeat .thediscussion `'of :these conditions at this-point. However,.if desiredboth thefiniection of steam and-the heatingrof the cushion canbeterminated well ahead of the opening of the mold. The molded cushioncan then be somewhat cooled by blowing'or sucking relativelycoolairfthrough it for several Vseconds before opening the mold. Amolded hair cushion C isindicated to the right of mold `P-in Fig. 3. ItVwill .Abe understood that the molded hair cushion is-then rpassed totavulcanizing or.curing oven such as oven 30 yof Fig. 2 to vulcanize theelastomer therein.

While in the foregoing specification `.specific embodi ments of thisinventionlhave lbeen set out in considerable detail for thefpurpose ofmore clearly illustrating the principle underlying this invention, itwill be understood that many of the `details set-forth ycan be varied`widely without departing from lthe spirit of this invention.

We claim:

l. In a method Vof making a compressed elastomerbonded hair product froma hairmat consisting of 4a stereoreticulate Vmass of curled animal hair`having a vulcanizable elastomer :distributed thereon, the steps Vofdrying said hair mat until said elastomerbecomes indispersible but thas`not appreciably vulcanized, subsequently increasing the moisturecontent of said hair by contacting it with an -atmosphere containingwater, and compressing said mat while .infsaid moist condition at atemperature of at least 21.2 1F., whereby said hair mat can -bepermanently set in compressed condition in a .very short interval oftime.

2. ln a method `of makinga compressed elastomerbonded hair productfromalhair mat consisting of a stereoreticulate mass of curled animal hairhaving Yan aqueous dispersion ofa vulcanizable elastomer distributed innodules at the intersections of the filaments, the steps of drying saidhair-mat `until said `elastomer reaches an indispersiblebutsubstantially unvulcanized state, subsequently increasing themoisturecontent of said hair to at least 15% by weight by contacting Vsaid yhairmat with an atmosphere containing steam, and compressing said mat whilein said moist condition at .a temperature of at least 230 F.,kwherebysaid hairmat can be permanently set in compressed condition in avery short interval of time.

3. The methodsteps of claim 2 in which said elastomer is a syntheticelastomer.

4. In a methodof `making a compressed elastomerbonded hair product vfroma 'hair mat consisting of a stereoreticulate mass of curled animal hairhaving an aqueous dispersion ofa vulcanizable elastomer 'distributed innodules at the intersections of the laments, the steps of drying saidyhair `mat until said yelastomer becomes indisperlsible but is notappreciably vulcanized, and then compressing said hair mat by contacting.it 4with at least one `surface heated to a temperature above 230 F.while simultaneously injecting steam -into said mat .to vincrease themoisture content thereof, -whereby said hair mat can be completely setin compressed condition in a very short interval of time.

5. The method steps of claim in which saidelastomer is a syntheticelastomer.

6. In a method of making a compressed elastomerbonded hair product from.a hair mat consisting primarily of a stereoreticulate mass of curledhog .hair hav- `ing an aqueous dispersion of a .vulcanizable elastomerdistributed on the` hairflarnentsand formed-into nodules at theintersections ofthe 'laments, said mat of curled hog hair being .intheformio'f va flat, thin .web, vthe steps of drying said hair mat untilsaid ,elastomer reaches an indispersible unvulcanized condition, thencompressing said mat to reduce its Vthickness and :increase its densitybycontacting atleast .one of the fiat` surfaces of said mat withasurfaceat a .temperature of .at least :230 F. while `simultaneously injectingsteam into .said mat to increase 2u,so34,577

the moisture content of the hair filaments therein to at least 15% byweight, whereby said hair mat can be permanently set in a highlycompressed condition in a very short interval of time, and subsequentlyvulcanizing said elastomer.

7, The method steps yof claim 6 in which said elastomer 1s a syntheticelastomer.

8. In a continuous process for making an under-rug pad from a hair webconsisting of a stereoreticulate mass ot curled animal hair having anaqueous dispersion of a vulcanizable elastomer distributed in nodules atthe intersections of the hair filaments, the steps of continuouslypassing said web through a drying zone wherein said elastomer is driedto an indispersible but substantially unvulanized state, thereaftercontinuously passing said dried web over a compressing roll having itssurface heated to a temperature of at least 230 F., compressing said webagainst the surface of said roll while simultaneously injecting steaminto said web, whereby said hair web can be permanently set in acompressed condition in a very short interval of time, and subsequentlyvulcanizing said elastomer to make said compressed web suitable for useas an under-rug pad.

9. The method steps of claim 8 in which said elastomer is a syntheticelastomer.

10. In a method of making a curvilinear elastomerbonded hair productfrom a rectilinear hair mat consisting of a stereoreticulate mass ofcurled animal hair having an aqueous dispersion of a vulcanizableelastomer distributed in nodules at the intersections of the hairfilaments, the step of compressing said rectilinear hair mat in a moldhaving at least one of the molding surfaces thereof heated to atemperature above 230 F. while simultaneously injecting steam into saidmat, whereby a curvilinear shape can be permanently impressed on saidrectilinear hair mat in a very short interval of time.

References Cited in the file of this patent UNITED STATES PATENTS2,430,868 Francis Nov. 18, 1947 2,455,534 Talalay Dec. 7, 1948 2,480,851Goss Sept. 6, 1949 2,502,361 Zeigler Mar. 28, 1950 2,541,868 Gordon Feb.13, 1951 2,580,202 Talalay et al. Dec. 25, 1951 2,582,915 Sebok Jan. 15,1952

1. IN A METHOD OF MAKING A COMPRESSES ELASTOMERBONDED HAIR PRODUCT FROMA HAIR MAT CONSISTING OF STEREORETICULATED MASS OF SUSRLED ANIMAL HAIRHAVING A VULCANIZABLE ELASTOMER DISTRIBUTED THEREON, THE STEPS OF DRYINGSAID HAIR MAT UNTIL SAID ELASTOMER BECOMES INDISPERSIBLE BUT HAS NOTAPPRECIABLY VULCANIZED, SUBSEQUENTLY INCREASING THE MOISTURE CONTENT OFSAID HAIR BY CONTACTING IT WITH AN ATMOSPHERE CONTAINING WATER, ANDCOMPRESSING SAID MAT WHILE IN SAID MOIST CONDITION AT A TEMPERATURE OFAT LEAST 212*F., WHEREBY SAID HAIR MAT CAN BE PERMANENTLY SET INCOMPRESSES CONDITION IN A VERY SHORT INTERVAL OF TIME..